Electroluminescent lamp



March 8, 1960 B. E. BARTELS 2,928,015

ELECTROLUMINESCENT LAMP Filed March 26, 1959 INVENTOR BERN/MRO 1-. 5427515 ATTpRNEY 2,92 s,01s -amcraoromns cnm LAMP Bernhard E. Bartels, Glen Cove, N.Y., assignor to Sylvania Electric Products In'c., a corporation of Delaware My invention relates to electroluminescent lamps'..

As i's known to the art, an electroluminescent lamp comprises first and second spaced apart'electrodes; at least one of which permits the passage of light therethrough. A solid electroluminescent layer is interposed between and in contact with. bothfelectrodes. (This layer is either composed entirely of an electroluminescent phosphor or a dispersion of electroluminescent phosphor particles-in dielectric material.) When a voltageis applied between the electrode, light is emitted from the electroluminescent layer. r

I have invented a new typeof electroluminescent lamp which is flexible and. can be constructed to conform to' flat or curved receiving supports. My lamp can be cut Unite. .States Patent light'is produced.

the bottom surface of. sheet 1 0 -Typically, the electro luminescent layer is constituted by a dispersion of copper activated'zinc sulfide electroluminescent phosphor parti l cles in a flexible dielectric. (For example, the dielectric can be a plastic or ceramic film.)

When an'alternatingvoltage 1S applied between termi-i nals 30 and 32, an electric field is established between. eaclrelectrode set formed by an odd numbered electrode 3 and an'adjacent even numbered electrode. This field en- ,ergiz es that portion of the electroluminescent layer 34 dis- Y posed between the electrodes of each-electrode set, and

The lamp thus produced can be; cut or trimmed readily to produce variously shaped surface areas of different sizes. Further the flexible sheet can be secured to flat or curved surfaces. v What is claimed is:

1'. An electroluminescent lamp cornprising a flexible sheet of an electrically non-conductive material, the'op of the other surface; a plurality of electrodes, one electrode being positioned within each groove, of said one surface; and an electroluminescent layer applied over said "other surface andfilling the grooves thereof.

' 2. An electroluminescent lamp comprising a flexible or shaped so that the shape or size of the light emitting surface can be varied as required. vjMoreover, my lamp can be constructed simply and inexpensively.

In accordance with the principles of my invention, my electroluminescent lamp includes a'flexible sheet of an electrically non-conductive material- The two opposite surfaces of this sheet are provided with a plurality of ridges and grooves, the ridges and grooves ofone surface respectively constituting the grooves and ridges of the other'surface. My'lamp further includes a plurality of electrodes, one electrode beingpositioned within each groove of the one sheet surface. An electroluminescent layer is applied over the other surface and fills the grooves thereof.

The even numbered electrodes are connected in common to a first common terminal. The odd numbered electrodes are connected in common to a second common terminal. When an alternating voltage is applied between the first and second terminals, light is emitted from the electroluminescent layer,

Since the sheet is flexible, the lamp so constructed can be readily curved or bent. Further, the size or shape of the light emitting surface can be varied by appropriately cutting or shaping the lamp.

An illustrative embodiment of my invention will now be described with reference to the accompanying figure.

Referring now to the figure, there is shown a corrugated flexible sheet 10 formed from'an electrically nonconductive material of high dielectric strength, as, for example, a sheet of polyethylene terephthalate,

The bottom surface of sheet 10 is provided with a plurality of ridges 12, 14 and 16 and a plurality ofinterposed grooves 18, 20, 22 and 24. An electrode formed, for example, of tin oxide is positioned within each of these grooves. Thus, there are four electrodes 26, 27, 28 and 29 respectively positioned within grooves'18, 20, 22 and 24.

The even numbered electrodes 26 and 28 are connected sheet of an electrically non-conductive material, the opposite surfaces of said sheet being provided with a pluralif ity of ridges and grooves, the'ridges and grooves of one surface respectively, constituting the grooves and ridges of the other surface;'a plurality of electrodes, one electrode being positioned within each groove of said one surface,

the even numbered electrodes being connected in common to afirst terminal, the odd numbered electrodes being connected in common to a second terminal; and an electroluminescent layer applied over said other surface and filling the grooves thereof.

'3. An electroluminescent device comprising a flexible sheet of an electrically non-conductive material, the opposed surfaces of said sheet being provided with a plurality of ridgesiand grooves, the ridges and grooves of one surface respectively constituting the grooves and ridges of the other surface; a plurality of electrodes, one electrode being positioned Within each groove of said one surface, the even numbered electrodes being connected in common to a first terminal, the odd numbered electrodes being connected in common to a second terminal; an electroluminescent layer applied over said other surface and filling the grooves thereof; and means to apply an alternating voltage between said first and second terminals whereby light is emitted from said layer.

4. An electroluminescent lamp comprising a corrugated flexible sheet of an electrically non-conductive material; a plurality of electrodes, each electrode being positioned within a separate groove on one surface of said sheet; and an electroluminescent layer coveringthe opposite surface of said sheet.

5. An electroluminescent lamp comprising a corrugated sheet of polyethylene terephthalate; a plurality of electrodes, each electrode being positioned within a separate groove on one surface of said sheet; and an electroluminescent layer covering the opposite surface of said sheet.

References Cited in thefile of patent UNITED STATES PATENTS 2,684,450 Mager July 20, 1954 2,768,310 Kazan Oct. 23, 1956 2,838,715 Mager June 10, 1958 PatentedfMai- 8,1960 

